This invention relates to the detection of variations in human histamine H2 receptors, and more particularly to the development of new compounds useful in the sequencing and identification of a human histamine H2 receptor and their use in the diagnosis and treatment of certain human disorders, for example, brain disorders. The invention also relates to new compounds and a method for detecting an allelic polymorphic variation within the human population for the gene encoding the histamine H2 receptor, and their use in the diagnosis and treatment of human disorders.
The histamine H2 receptor is one of many receptors in the body. Compounds used to treat many diseases work by activating a receptor or inhibiting the action of its natural ligand. Variations in some receptors amongst the population are known to be caused by allelic variation, and this variation can alter the response of a disease to a drug amongst patients. An example of this would be the response to clozapine, used to treat schizophrenia, associated with allelic variation in the 5-HT2A receptor demonstrated by Arranz el al (1995) Lancet, 346(8970), 281-282.
In co-pending UK Patent Applications Nos. GB9503866.7 and GB9522889.6, and in International Patent Application No. PCT/EP96/00397, it is reported that there is a hitherto unrecognised allele or subtype of the human histamine H2 receptor gene which may be specific to the brain.
In the above mentioned co-pending patent specifications there are described and claimed:
1) a sequence for a novel allele of a human histamine H2 receptor gene comprising up to six single base substitutions compared with the cDNA sequence published by Gantz et al (1991) Biochem Biophys Res Comm 178,3,1386-1392 as follows:
The cDNA sequence in Gantz et al., supra, is:
This cDNA sequence encodes the following amino acid sequence:
2) a nucleotide sequence coding for a region of a human histamine H2 receptor, comprising one or more of the following base substitutions compared with the published sequence in Gantz et al (1991) supra, and from which the positional notation is taken:
The nucleotide sequence can, for example, comprise the following sequence (as listed in SEQ ID NO: 1):
As a specific exemplification, the nucleotide sequence can comprise the following sequence (as listed in SEQ ID NO: 2):
3) new oligonucleotides, suitable for use as primers for the amplification of DNA corresponding to a region of a human histamine H2 receptor, having nucleotide sequences selected from:
1) 5xe2x80x2 CCAATGGCACAGCCTCTT 3xe2x80x2 (as listed in SEQ ID NO: 3)
2) 5xe2x80x2 CGTGACTTCTGTCCCACT 3xe2x80x2 (as listed in SEQ ID NO: 4)
3) 5xe2x80x2 CCAGGCAACAGGAAGAGA 3xe2x80x2 (as listed in SEQ ID NO: 5)
4) 5xe2x80x2 TCTCTTCCTGTTGCCTGG 3xe2x80x2 (as listed in SEQ ID NO: 6)
5) 5xe2x80x2 GCAGCAGAAGAGCTGTTG 3xe2x80x2 (as listed in SEQ ID NO: 7)
6) 5xe2x80x2 TCCAGGTCAATGAAGTGT 3xe2x80x2 (as listed in SEQ ID NO: 8)
7) 5xe2x80x2 ACACTTCATTGACCTGGA 3xe2x80x2 (as listed in SEQ ID NO: 9)
8) 5xc2x0 CCAAGAGGATCAATCACA 3xe2x80x2 (as listed in SEQ ID NO: 10)
9) 5xe2x80x2 TGTGATTGATCCTCTTGG 3xe2x80x2 (as listed in SEQ ID NO: 11)
and
4) a diagnostic kit comprising one or more of the above new oligonucleotides.
The present invention is concerned in one aspect with improvements in the diagnosis and/or treatment of human neurological and psychiatric disorders, and more particularly in the diagnosis and treatment of schizophrenia. In another aspect, the invention is concerned with improvements in the diagnosis and/or treatment of diseases of other systems or organs of the human body.
According to the invention, a further group of oligonucleotides has now been developed for the identification of sequences in a sample comprising a human histamine H2 receptor DNA, cDNA or RNA originating from a tissue sample or body fluid.
In a first aspect, therefore, the invention provides new oligonucleotides, suitable for use as primers for the amplification of DNA corresponding to a region of a human histamine H2 receptor, having nucleotide sequences selected from:
10) 5xe2x80x2 ACACCAGCCTGGATGTGA 3xe2x80x2 (as listed in SEQ ID NO:12)
11) 5xe2x80x2 TCACATCCAGGCTGGTGT 3xe2x80x2 (as listed in SEQ ID NO:13)
12) 5xe2x80x2 CAATCATACCACCTCTAA 3xe2x80x2 (as listed in SEQ ID NO:14)
13) 5xe2x80x2 ACACAAACGCGGTGAAGT 3xe2x80x2 (as listed in SEQ ID NO:15)
15 and a diagnostic kit comprising one or more of the above mentioned oligonucleotides.
The direction and base start numbers for the novel oligonucleotide primers are as follows:
Information on the human histamine H2 receptor was obtained from the MRC Daresbury database accessing xe2x80x9cGenem 61xe2x80x9d File no. M64799xe2x80x94Human histamine H2 receptor gene.
The above mentioned substitutions in the human histamine H2 receptor gene alter and in some instances introduce or remove new sites for cleavage by specific restriction endonucleases as follows:
In another aspect the invention provides a diagnostic kit comprising one or more of the new oligonucleotide primers and, preferably, one or more of the above mentioned endonucleases, optionally with one or more buffers.
In a still further aspect, the invention provides a diagnostic kit comprising one or more of the new oligonucleotide primers whereby detection of human histamine subtypes can be achieved using single-stranded conformational polymorphism (SSCP). The kit can, for example, comprise one or more of the above mentioned oligonucleotide primers, and, optionally, formamide.
A kit may be used to establish genotype or base variations. This information may be used in predicting an individual""s disease susceptibility, disease course, prognosis and/or response to treatment, as would be understood by those skilled in the art from the disclosure contained herein. The treatment response or efficacy which may be predicted may include drug treatment such as for example, use of H2 receptor antagonists, for example, famotidine, or other forms of treatment such as social or psychological intervention.
Eucaryotic expression vectors and host cells transformed thereby can be prepared as described in the above mentioned co-pending patent specifications and the encoded protein analysed.